Method of setting drillable liners in wells



June 18, 1940. E. B. HALL Er AL vMETHOD 0F SETTING DRILLABLE LINERS IN WELLS 2 sheetsl-sneet 1 Filed April 1'7, 1939 June 18, 1940. E. B. HALL ET AL METHOD oF SETTING DRILLABLE LINERs IN WELLS 2 Sheets-Sheet 2 Filed April 17, 1939 a L. 4\m

Patented June 18, 1940 v mmLABLE LINE'as wELLs. Elwin n. Hau and Arthur L. Armentmut, Los

Angeles, Calif.,m assignors',

by direct and mesne assignments, to Security Engineering Co. Inc.,

a corporation of Califo Appneetion April 1v, 1939,ser1a1na 268,306 s claims. (ci. isc-1) This-invention relates to a method of setting readily drillable liners'in wells sidered as a continuation in part of the subject matter disclosed our copending application entitled Drillable well liner, Serial No. 185,530,

filed January 18, 1938, now Patent No. 2,155,129,

granted April 18, 1939.

An' object of the invention is to provide a novel method of setting a readily drillable well liner in a well. In the conventional well the casing is formed of steel.A As disclosed in our copending application above referred to, a highly satisfactory liner formed.. of certain types of aluminum alloys may be set in the well so as to extend downwardly below rosion by ordinary fluids under the 'conditions that may be normally encountered in oil wells. Such liners possess the properties of being readily drillable by conventional well drilling equipment and have a suciently low specific gravity so that theV cuttings may be .readily flushed out of the well by the circulation fluid. Consequently, by the use of such ,a liner, whenever it is desired to remove the liner for any purpose, as for example deepening the well, the liner may be readily drilled up and the cuttings Kflushed out.

With the liner being formed of ai metal unlike that of the steel of the casing' and with the liner in contact with the casing a type of galvanic action is set up between these contacting unlike the casing and will resist cor-f and may be conmetals immersed in the oil well fluid. It some -times' also occurs that currents may be induced or imposed so that a form of electrolytic action takes place. It is an` object of the present. invention to provide a method of setting, liners in a well which contemplates the use of a readily vdrillable liner formed of a material unlike that of the steel casing wherein the liner is set in such a manner as to avoid the setting up ofthis galvanic or electrolytic action. Inasmuch as the liner itself is readily drillable the invention' contemplates cementing in place without physical contact casing. The presence of the cem terfere-with the drilling up of the upper end of the liner he liner when with the stel t does not inoccasion requires, and the surrounding body of cement contributes tothe formation of a cement seal isolating water-bearing sands or formations from the oil o r production zone.

With the foregoing and other objects in View, which will be made manifest in the following detailed description and .specifically pointed out in the appended claims, reference is had to the accompanying drawings for an illustrative embodiment of the invention, wherein:

Figure 1 is a vertical section through the lower portion of a well illustrating the casing as having been cementedin place and illustrating the liner as having been run into the well to the desired o0 position;

Fig. 2 is a view similar to Fig. 1, but illustrating the manner in which the liner is set in po-v sition by means of cement;

Fig. 3 is a view simuar to Fig.v 1 inustrating the cementing operation as having been com-.r

pleted; t Fig. 4 is a view similar to Fig. 3 illustrating the completion of the operation for setting the liner;

Referring' to .the accompanying drawings wherein similar 'reference characters designate similar parts throughout, the reference character III indicates a steel casing which may` have been cemented in placein a well as by cement II. The linerl is generally designated at I2 formed of a plurality of tubular sections of read ily drillable material. The material employed is preferably one of the alloys disclosed in our copending application inasmuch as those alloys--possess the properties of required strength, corrosion resistance, drillability, and low specific gravity. However, in the performance of this invention other materials may be employed, either Vmetallic or non-metallic, and if,metal1ic, aluminum alloys other than those disclosed inour copendinggapplication may be employed if resistance to corrosion is sacrice'd.

,The liner illustrated has an upper imperforate section I3 and lower perforated sections III. At the bottom of the limperforate section there is a cotlar I5 provided with cementing ports I6 and Awith adrillable baille plate I1 in which is seated a cementingvalve I8. The cementing valve may be of any desired or preferred construction,` the one illustrated being so designed as to permit upward flow through the liner while the liner is being lowered into the well but to prevent downward flow past theA bale/ plate during cementing operations.' At the top of the liner there is an adapter I9 `also formed of readily drillablematerial. The liner is optionally but preferably equipped'with a cement basket 2D immediately below collar I5 which. will prevent cement from being forced downwardly aboutthe liner theresmaller than the interior of the casing, the Airi'v tention being that when the.y liner is set the adapter will be out of contact with the casing. However, as the/ adapter occupies a, large portion vof the interior' of the casing it serves to some extent confine the cement between the adapter and the cement basket 20. 1

`lbemw. The liner-is' lowered finto Vme wen by With the liner installed in the well by means of the run-in string of pipe 2|, asshown in Fig. 1, cement is then forced downwardly through the run-in string of pipe and is discharged therefrom above the cementing valve I8. The cement is forced outwardly through the ports I6 and as it cannot flow downwardly past the cement basket 20 it flows upwardly completely, filling the space between the upper portion of the liner and the well walls and filling` the space between the top of the liner and the bottom of the casing below adapter i9. When the cement is completely discharged the run-in string of pipe is rotated to disconnect the setting tool 22 therefrom and the run-in string of pipe is pulled upwardly ashort distance and circulation therethrough is reestablished.

As the packing means 24 is pulled out of the liner and circulation fluid is discharged therethrough, the top of the liner is effectively cleaned of cement. Circulation is continued to wash away excess cement that may be in the casing above the adapter after which the run-in string of pipe is withdrawn and the cement is allowed to set leaving the well in the condition as shown in Fig. 3. In this condition, it will be noted that thereis a small amount of cement in the liner immediately above the cementing valve I8. A bit 25 is then lowered into the well b y means of a drill pipe 26 and the cement remaining in the liner, the cementing valve I8, and the baille plate l'lris drilled. out after which the well is in condition to be placed on production.

It will be noted that by this method of setting a liner that if for anyreason it should be desired to remove the liner, the adapter, liner, cement basket, and the surrounding cement indicated at 21 can be readily drilled out leaving the well in excellent condition for further operations. While the liner remains set in the well, it will be noted that there is no contact or electrical connection between the linerand the casing. Consequently, even though the liner may be of a metal unlike that of the steel casing, and would be such that either a galvanic action or an electrolytic action might take place under certain conditions, the interposed body of cement prevents the presence of an electrolyte between the casing and the liner. I n addition, the cement body at' 21 cooperates with the cement Il in maintaining a cement sealI shutting off communication between any upper water-bearing strata and the desired oil or producing zone..

The term cement a's used herein is intended to include any substance used forcementing casings in wells, but in order to gain the advantage of preventing galvanic action or lelectrolytic action between the' liner and the casing the cement employed should either be a non-conductor of4 electricity or an extremely poor one, and should be impervious to conducting fluids or liquids that might constitute ani electrolyte between the liner and casing.

From the above-described construction and conditions, be conducive to the setting up of the galvanic or electrolytic action, that the liner is set in such a manner that the galvanic or electrolytic action in fact will not be set up. At the same time, however, it is possible at all times to readily remove the liner but as long as the liner remains in thewell it is firmly positioned by cement which contributes to effecting a water shutoff.

Various changes may be made in the details of construction without departing from the spirit or scope of the invention as defined by the appended claims.

1. The method ofsetting a readily drillable liner in a well which includes forcing cement into the space between that portion of the liner that extends up into the casing and the casing and allowing the cement to set.

2; The method of setting in a well a readily drillable liner formed of a metal unlike that of the metal of the casing so as to retard or prevent and the bottom ol' the casing in such a manner that the liner will be held out of contact with the casing. y'

i 4. A well liner formed of readily drillable metal having a readily drillable cementing valve therein t adjacent the upper portion thereof, ports in the walls of the liner above the cementing valve and a cement basket ony the exterior of the liner below the ports.

5. A well liner formed of readily drillable material having a readily drillable cementing valve therein adjacent the upper portion thereof, and ports in the walls of the liner above the cementing valve.

6. A well liner formed of readily drillable metal having a readily drillable cementing valve therein adjacent the upper' portion thereof, and ports in the walls of the liner above the cementing valve.

7. The method of setting in a well a readily drillable liner formed of a metal unlike that of the metal of the casing so as to retard or prevent galvanic or electrolytic action that might take place between the unlike metals which method comprises cementing between the upper portion of the liner and the well walls and having the cement extend up into the space between the top of the liner and the bottom of the casing.

8. The method of setting in a well a readily drillable liner formed of a metal unlike that of the metal of 'the casing so as to retard or prevent galvanic or electrolytic action that might take place between the unlike metals which method comprises cementing between the upper portion of the line!` and the well walls and having the cement extend up into the space between the top of the liner and` the bottom of the casing so as to occupy all of the space between the top of the liner and the bottom of the casing.

ELWIN B. HALL. ARTHUR, L. ARnmN'I'RoUT. 

